Spring habitats in woodland and grassland areas are part of the fresh water system, marking the spots where ground water discharges and becomes surface water. Ecologically they are characterized by water temperatures that are relatively low in the summer and relatively high in the winter, supporting plant species that are tolerant of low temperatures around their roots at all times. Ground water, by nature, is poor in nutrients, so that net primary production is low. For this reason, the typical plant species in spring habitats do not suffer from strong competition. The most widespread communities of spring habitats belong to the Montio-Cardaminetea and contain only plant species with low demand on temperature and nutrient supply.
Some 1,800 relevés, of which more than 900 were processed in vegetation tables, were the basis of this investigation into the vegetation of spring habitats in Germany. The comparison of the relevés lead up to a distinction on the high syntaxonomical level of orders, dividing spring vegetation in woodland areas, on one side, from spring vegetation in grassland habitats, on the other side. Spring vegetation in grassland habitats is subdivided into thee alliances with 11 associations a total of, whereas, spring vegetation in woodland areas comprises only one alliance with two associations. Relevant parts of the syntaxon descriptions are syntaxonomy and nomenclature, floristic characterization and differentiation. Furthermore, investigations of vegetation structure and ecology are presented to underpin the syntaxonomical differentiation. Further information is added on vegetation dynamics, distribution, economic importance, zoocenology, and nature conservation. For each alliance and for the class a vegetation table with constancy values is provided. In addition, tables with average ecological parameters describe the ecological conditions for the given syntaxa. An overview of the syntaxa and their diagnostic species simplifies the determination and shows the floristic peculiarities of Montio-Cardaminetea.
Keywords: Montio-Cardaminetea, Germany, syntaxonomy, classification, vegetation structure, ecology, dynamics, distribution, biocenology, nature conservation.